MageCraft is currently in Alpha, and very much a work in progress, so expect this documentation to change quite a bit.
Currently, only the Alchemy system is implemented, but I am planning on adding a mana based spellcasting system as well. Also note that there aren't any textures for items yet, but I plan to add them in the next patch.
In the current version (0.2.1d) you'll find the basics of the Alchemy system. More advanced Alchemy, power items, and more functionality for existing items is planned.
Crafting Recipes and Design Documents can be found here: http://pastebin.com/SaYrpWyJ and here: http://pastebin.com/h3NQLKfH
Installation is standard, simply install Forge and drop MageCraft in the mods folder. Version 0.2.1d is compatible with both Minecraft 1.4.6 and Minecraft 1.4.7. Note that items ids 26200 through 26210 are the defaults used for this mod, although they can be configured.
If you find a bug, or think I missed an Essence recipe, let me known. Bug reports should include an error log and a description of the problem.
Download Version 0.2.1d: http://bit.ly/15GsJf3
If you need to contact me for any reason, you can send me a PM on the forum. I also can be found in #GreenWolf13sMods on SynIRC.